Inventors of the present application have been proposing technologies for a sheet-like (cloth-like, paper-like, foil-like, plate-like, film-like, or mesh-like, one dimensioned as a plane but having a thin thickness) communication device having a plurality of communication elements embedded therein. For example, the following literature discloses a communication device having a plurality of communication elements, embedded in a sheet-like member (hereinafter, a “sheet-like body”), relay a signal without individual wirings, thereby transmitting the signal.
Patent Literature 1: Japanese Unexamined Patent Application KOKAI Publication No. 2004-007448
According to the technology disclosed in the [patent literature 1], communication elements are disposed at respective vertexes of a figure formed in a grid-like shape, a triangular shape, or a honeycomb-like shape on the surface of the sheet-like body. A communication element utilizes a change in a potential, which is generated by the communication element and propagates strongly nearby but attenuates distantly, and communicates another communication element only.
By successively transmitting a signal between individual communication elements through local communications, the signal is transmitted to a target communication element. The plurality of communication elements are hierarchized by a management function, path data is set for each hierarchy, so that a signal is efficiently transmitted to a final-destination communication element.
On the other hand, developed through the researches of the inventors is a technology such that an electromagnetic field is generated at a region sandwiched between sheet-like bodies facing with each other, and the electromagnetic field is made progress by changing the electromagnetic field through a change in a voltage between the two sheet-like bodies, and by changing the voltage between the sheet-like bodies through a change in the electromagnetic field, thereby performing communication.
To detect a voltage between the two sheet-like bodies, in general, a communication device is directly connected to both sheet-like bodies via wires, and the sheet-like body is provided with a connector which is to be connected to the communication device.